The present invention relates to semiconductor die packages and, more particularly, to modular semiconductor die packages for light emitting and/or light receiving semiconductor devices, such as laser diodes and photodetectors, and methods of manufacturing thereof.
Optical transmitters and optical receivers are widely used in a variety of applications including, for example, telecommunications, computing, entertainment, and medical devices. Laser diodes, such as Vertical Cavity Surface Emitting Lasers (VCSELs), are frequently mounted in Transistor Outline style cans (TO-cans). TO-cans for optical applications are metal packages that typically have a windowed top, allowing light to pass through. There are several industry standard metal TO-cans available in different base diameters and lead configurations, including, for example, the TO-46 flat window metal can. Other packages include TO-3 packages, used for higher power laser diodes. Conventional TO-packages are typically costly to manufacture due in part to a lack of modularity in design, and therefore do not lend themselves to economies of scale in production.
Conventional metal TO-cans used for semiconductor lasers or detectors have a window arranged in a plane perpendicular to the emitting direction of the laser beam. In order to prevent light reflecting from the window from reentering the semiconductor emitting device and interfering with or damaging the laser, anti-reflection (AR) coatings are applied to the window. However, AR coatings may contribute significantly to the per unit cost of production, since they require additional processing steps to manufacture. Accordingly, a need exists for a cost-effective method of preventing light reflected from the window of the package from re-entering and interfering with the light emitting semiconductor device, while maintaining high coupling efficiency, low insertion loss, and without requiring the use of anti-reflective coatings on the window of the package.
In certain optical communications systems, for example, signaling speeds may reach or exceed 10 GHz, or even 40 GHz. Consequently, there exists a need for precision modular packages with leads capable of accommodating the high speed signaling requirements associated with optical applications without generating unwanted RF interference.
Further, because conventional metal TO-cans were originally intended to house transistors, not precision optical components requiring exacting alignment, metal TO-cans often do not provide the high tolerances required for automated assembly in optical applications. For example, when metal TO-can packaging is used, manual alignment of the semiconductor device and the package is often required during production to ensure critical tolerances are maintained, making automation impractical and increasing manufacturing costs. Conventional semiconductor laser packaging, such as metal TO-cans, suffer from other disadvantages including high material cost and the need for special fabrication steps to integrate glass or plastic windows onto the metal can packaging.
Accordingly, there is a need for improved optical semiconductor packaging and methods of manufacturing that afford high degrees of automation and economies of scale, while providing increased precision and tolerancing in the finished product with less waste of materials. A further need exists for modular packaging that may accommodate different mounting techniques (e.g., surface mount, through-hole mount, etc.) in a common package design. A need also exists for a modular package design that allows separate processing of cumbersome elements, such as pin extensions for through-hole mounting, until final assembly of the package.
A semiconductor die package is provided. The semiconductor die package includes a polymer base comprising a lower surface and an upper surface, the upper surface for mounting at least one semiconductor die. A polymer cap is operatively secured over at least a portion of the upper surface of the base forming a cavity, the cap having a light transmissive member operatively positioned to allow light of predetermined wavelengths to pass between at least a portion of the upper surface of the base and the light transmissive member. A plurality of conductive leads extend through the base from the lower surface of the base to the cavity.
A matrix of semiconductor die packages is also provided. The matrix of semiconductor die packages includes a base matrix comprising a plurality of polymer bases, each base comprising a surface for mounting at least one semiconductor die. The matrix of semiconductor die packages also includes a cap matrix comprising a plurality of polymer caps operatively secured over the base matrix, each base and cap combination forming a cavity, each cap having a light transmissive member operatively positioned to allow light of predetermined wavelengths to pass between the surface for mounting at least one semiconductor die of a corresponding base and the light transmissive member. A plurality of conductive leads extend through each base from an outside surface of each base to the corresponding cavity formed by each cap and base combination.
A method of making a semiconductor die package is further provided. The method of making a semiconductor die package includes forming a polymer base comprising a lower surface and an upper surface, the upper surface for mounting at least one semiconductor die; forming a polymer cap operatively secured over at least a portion of the upper surface of the base forming a cavity, the cap having a light transmissive member operatively positioned to allow light of predetermined wavelengths to pass between at least a portion of the upper surface of the base and the light transmissive member; and forming a plurality of conductive leads extending through the base from the lower surface of the base to the cavity.
A method of making semiconductor die packages is also provided. The method of making semiconductor die packages includes forming a base matrix comprising a plurality of polymer bases, each base comprising a surface for mounting at least one semiconductor die; forming a cap matrix comprising a plurality of polymer caps operatively secured over the base matrix, each base and cap combination forming a cavity, each cap having a light transmissive member operatively positioned to allow light of predetermined wavelengths to pass between the surface for mounting at least one semiconductor die of a corresponding base and the light transmissive member; and positioning a plurality of conductive leads extending through each base from an outside surface of each base to the corresponding cavity formed by each cap and base combination.